Finger guard for power distribution panel

ABSTRACT

A finger guard for an electrical circuit breaker includes a rear plate with an opening, a guard portion extending from the plate adjacent the opening, and a removable portion, or knock-out, positioned within the opening. A further finger guard for an electrical circuit breaker includes a rear plate with an opening, a guard portion extending from the plate adjacent the opening, and opposing ramped finger grips on the outer walls of the guard portion. A further finger guard for an electrical circuit breaker includes a rear plate with an opening, and a guard portion extending from the plate adjacent the opening, the plate further including a designation holder. An electrical power distribution system with a chassis having an electrical circuit including a mount for an electrical circuit breaker and an opening providing access to the mount, includes a finger guard mounted across the opening. A method of removing a finger guard from an opening on an electric power distribution chassis, removing a portion covering an opening in the finger guard, mounting the finger guard to an electrical circuit breaker, and inserting the electrical circuit breaker into a circuit breaker mount in an electrical circuit within the chassis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/932,466, filed on Aug. 17, 2001, now issued as U.S. Pat. No.6,870,729, on Mar. 22, 2005, the disclosure of which is incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention relates to power distribution units. Morespecifically, the present invention relates to providing finger guardsfor circuit breakers used with power distribution units.

BACKGROUND OF THE INVENTION

Power distribution units are used to distribute power supplied by a mainelectrical source to a variety of devices requiring power. The powerdistribution unit may include an internal power bus that powers one ormore circuits. Each of these circuits may include a protective device,such as a fuse or a circuit breaker, which is accessible through one ofthe walls or panels of the unit. A power distribution unit may have thecapacity for more circuits than are required when the unit is installed,which provides for future expansion. In such installations, one or moreof the circuits may be left open, that is, without having any protectivedevice.

The openings through which these omitted protective devices will extendare often covered to prevent unwanted or accidental contact with thepower bus within the unit. This may be done with a flat plate or blankcover secured over the opening. When a protective device is insertedinto the opening to provide an additional power circuit, this blank isthen removed and discarded. A mounting plate may then be attached to theprotective device and the device inserted into the power distributionunit. When a switched circuit breaker is the protective deviceinstalled, the mounting plate may incorporate a finger guard structureto protect the switch from accidental contact opening the circuit andinterrupting power in the circuit.

Several concerns arise in the area of finger guards, including ease ofuse and reliability. Providing separate mounting plates and blank coverscan be difficult to coordinate and manage, especially when the circuitprotective devices are added later. Further developments in fingerguards are desired.

SUMMARY OF THE INVENTION

The present invention relates to a finger guard for an electricalcircuit breaker, the finger guard including a rear plate with anopening, a guard portion extending from the plate adjacent the opening,and a removable portion, or knock-out, positioned within the opening.

The present invention further relates to a finger guard for anelectrical circuit breaker, the finger guard including a rear plate withan opening, a guard portion extending from the plate adjacent theopening, and opposing ramped finger grips on the outer walls of theguard portion.

The present invention also relates to a finger guard for an electricalcircuit breaker, the finger guard including a rear plate with anopening, a guard portion extending from the plate adjacent the opening,and the plate further including a designation holder.

The present invention relates as well to an electrical powerdistribution system with a chassis having an electrical circuitincluding a mount for an electrical circuit breaker and an openingproviding access to the mount, a finger guard mounted across theopening, the finger guard including an opening covered by a removableportion.

The present invention also relates to an electrical power distributionsystem with a chassis having an electrical circuit including a mount foran electrical circuit breaker and an opening providing access to themount, a finger guard mounted across the opening, the finger guardincluding opposing ramped finger grips on the outer walls of the guardportion.

The present invention further relates to an electrical powerdistribution system with a chassis having an electrical circuitincluding a mount for an electrical circuit breaker and an openingproviding access to the mount, a finger guard mounted across theopening, the finger guard including a designation holder.

The present invention relates as well to a method of removing a fingerguard from an opening on an electric power distribution chassis,removing a portion covering an opening in the finger guard, mounting thefinger guard to an electrical circuit breaker, and inserting theelectrical circuit breaker into a circuit breaker mount in an electricalcircuit within the chassis.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate several aspects of the inventionand together with the description, serve to explain the principles ofthe invention. A brief description of the drawings is as follows:

FIG. 1 is a front perspective view of a portion of a power distributionunit according to the present invention.

FIG. 2 is a front view of the power distribution unit of FIG. 1.

FIG. 3 is a side view of the power distribution unit of FIG. 1.

FIG. 4 is a bottom view of the power distribution unit of FIG. 1.

FIG. 5 is a side view of a finger guard according to the presentinvention mounted to a switchable circuit breaker and a schematicelectrical circuit including a circuit breaker mount for the powerdistribution unit of FIG. 1.

FIG. 6 is a front perspective view of a finger guard according to thepresent invention.

FIG. 7 is a front view of the finger guard of FIG. 6.

FIG. 8 is a side view of the finger guard of FIG. 6.

FIG. 9 is a rear view of the finger guard of FIG. 6.

FIG. 10 is a bottom view of the finger guard of FIG. 6.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary aspects of the presentinvention that are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

FIG. 1 shows a portion of a power distribution panel 10 for use in atelecommunications installation, such as a rack, to provide power toother devices within the same installation. Panel 10 includes protectivedevices in the form of circuit breakers and fuses. Typically on the rearof panel 10 is a power input connection 98 where a power supply feed isconnected. As shown in FIG. 5, an internal bus 100 distributes thecurrent provided through power input connection 98 into a series ofseparate distribution circuits 102. Each distribution circuit 102 iselectrically connected with a power output connection 112 by a lead 104.Power output connection 112 is also on the rear of panel 10, andprovides power to a device mounted elsewhere in the telecommunicationsinstallation. Distribution circuits 102 require a protective device suchas circuit breaker 30 be mounted in the distribution circuit to completethe electrical path and to provide over-current protection for thedistribution circuit.

Referring now to FIGS. 1 through 4, power distribution panel 10 includesa front face 12, a side 14, a top 16 and a bottom 18, along with a rearface and an opposing side which are not shown, forming an enclosure forthe power bus housed by panel 10. Finger guards 20 are mounted in anaccess opening 22 in front face 12. Behind each of six finger guards 20are mounts 110 to mount the protective devices completing and providingover-current protection for each of six internal distribution circuits102. Power distribution units may include more or less than the sixcircuits 102 shown. Also located on front face 12 are power indicatorlamp 24 and electrical fuse array 26, providing additional over-currentprotection to electrical circuits within power distribution panel 10.

FIG. 5 shows finger guard 20 mounted to the front of a protectivedevice, in this case a switched circuit breaker 30. Also shown is mount110 of distribution circuit 102 for receiving such a protective device.A pair of mounting studs 32, located at the rear of circuit breaker 30,interface with the stud receivers 106 which are part of mount 110.Insertion of mounting studs 32 in stud receivers 106 and placing switch33 of switched circuit breaker 30 into a closed position will completethe electrical path for each distribution circuit 102. Also located tothe rear of circuit breaker 30, between mounting studs 32, are alarmleads 34. Alarm leads 34 are received by alarm interface 108 of mount110 to provide a connection with alarm circuits 114 within powerdistribution panel 10. Alarm circuits 114 will initiate failure alarmswhen the current flowing through circuit breaker 30 is disrupted. Alsoshown in FIG. 5 are screws 21, which are discussed further below.

Referring now to FIG. 6, finger guard 20 includes a front face 44, arear face 46, side guards 36, a top wall 38 and a bottom wall 40cooperating to define an enclosure 42. A removable portion or knock-out56 closes a portion of the rear of enclosure 42 while the front ofenclosure 42 is open. A portion of the rear of the enclosure is openedby the removal of knock-out 56, forming an opening 57, through which aportion 31 of circuit breaker 30 extends, as shown in FIG. 5. Alsoextending from circuit breaker 30 through opening 57 into enclosure 42is switch 33 for setting circuit breaker 30 into an open or closedposition. The remainder of the rear of enclosure 42 is closed by frontface 44 and rear face 46.

At the bottom of finger guard 20 is located an indicia holder 48 throughwhich is formed opening 61. An indicia cover 52 removably mounts to thefront of indicia holder 48. Cover 52 can include indicia or it can betransparent to visible light for trapping a designation card 50 toidentify the circuit protected by circuit breaker 30. Cover 52 includesopposing edges 114 along the rear which engage lips 116 along the topand bottom of indicia holder 48 to securely and removably hold cover 52to indicia holder 48.

Located on the distal ends of the outer surfaces of top wall 38 andbottom wall 40 are opposing ramped finger grips 54. Ramped finger grips54 provide a positive and comfortable surface for grasping and removingcircuit breaker 30 connected to mount 110 inside power distributionpanel 10, when finger guard 20 is mounted to circuit breaker 30, asshown in FIG. 5. Ramped finger grips 54 may have ridges 55 formed in theramped surface, as shown in FIG. 8, or may be have some alternativesurface treatment to increase friction and improve grip.

Referring now FIGS. 7 through 10, mounting openings 60 extend from frontface 44 to rear face 46 of finger guard 20. Mounting openings 60 receiveremovable fasteners such as screws 21 for securing finger guard 20 tocircuit breaker 30. The upper mounting opening 60 is located withinenclosure 42 above knock-out 56. Openings 60 may be located in otherpositions along finger guard 20.

Knock-out 56 is joined to finger guard 20 by perforations, webbing orthinned portions 45, such as along the top and bottom of opening 57.Knock-out 56 is removed from opening 57 by applying force to knock-out56 from the rear sufficient to break thinned portions 45. Alternatively,notches 41 in knock-out 56 provide openings for the insertion of aflat-bladed tool such as a screwdriver from the front and apply force tothe rear of knock-out 56 using the leverage of the screwdriver to breakthinned portions 45. Finger guard 20 is made from molded plastic havingappropriate physical properties to permit the connection between fingerguard 20 and knock-out 56 to be broken along thinned portions 45 withthe application of reasonable force without damaging the remainder offinger guard 20.

Along the rear of finger guard 20 is a rear notch 64 in side guards 36.Rear notch 64 is sized to receive portion 31 of circuit breaker 30 whenfinger guard 20 is mounted to circuit breaker 30. Not all circuitbreakers include such an extension 31, having instead a flat front face.In addition, other protective devices may or may not have such anextension 31. Finger guard 20 is usable with such other protectivedevices, with or without an extension 31.

Side guards 36 include an arched portion 66 to provide additionalprotection to switch 33 of switched circuit breaker 30 extending intoenclosure 42. Arched portion 66 is shown coextensive with opening 57 andrear notch 64. Side guards 36 may have alternative shapes, either curvedor straight, provided that side guards 36 extend enough from front face44 to provide the desired protection to the switch 33.

Power distribution panel 10 may include one or more internaldistribution circuits 102 without a protective device such as circuitbreaker 30 completing the electrical pathway between the power inputterminal 98 and the power output terminal 112. In this case, opening 22in front face 12 proximate the mounts 110 for the protective deviceswill be covered by a finger guard 20, as shown in FIG. 2. Finger guard20 is held to front face 12 by a tab 62 inserted into a slot 68 throughfront face 12 above opening 22. Tab 62 includes a ramped portion 120which extends through slot 68 and engages the rear of front face 12.Opening 61 through indicia holder 48 also accepts a removable fastenersuch as a screw 21 which engages an opening 69 through front face 12below opening 22 to secure finger guard 20 to front face 12. Knock-out56 covers opening 57 and cooperates with front face 44 of finger guard20 when mounted to front face 12 of panel 10 to prevent accidental orunwanted contact with the electrical power components within panel 10.

To complete a distribution circuit, finger guard 20 is removed fromfront face 12 by removing the removable fastener such as screw 21 fromopening 69 and opening 61, and withdrawing tab 62 from slot 68.Knock-out 56 is removed from opening 57 by exerting force on the rear ofknock-out 56 and breaking thinned portions 45. Finger guard 20 in thenplaced on the front of a protective device such as circuit breaker 30 sothat portion 31, if present, extends into rear notch 64 and switch 33 ofcircuit breaker 30 extends into enclosure 42. Removable fasteners suchas screws 21 are then inserted through openings 60 to engage appropriateopenings in circuit breaker 30 to mount finger guard 20 to circuitbreaker 30. Circuit breaker 30 with finger guard 20 mounted to it isthen inserted through opening 22 in front face 12 of panel 10 so thatmounting studs 32 engage stud receivers 106 of mount 110 in distributioncircuit 102 and alarm leads 34 are received by alarm interface 108. Asthe circuit breaker is fully inserted into the mount, tab 62 of fingerguard 20 again engages an edge of slot 68 on front face 12 of panel 10and rear face 46 of finger guard 20 rests against front face 12. Aremovable fastener such as screw 21 is then inserted through opening 61to engage opening 69, securing finger guard 20 to front face 12.

With regard to the foregoing description, it is to be understood thatchanges may be made in detail, especially in matters of the constructionmaterials employed and the shape, size and arrangement of the partswithout the scope of the present invention. It is intended that thespecification and depicted aspects be considered exemplary only, with atrue scope and spirit of the invention being indicated by the broadmeaning of the following claims.

1. A finger guard for an electrical circuit protection device, thefinger guard comprising: a body defining a protection device receivingregion; a removable portion blocking receipt of the protection device inthe protection device receiving region; a designation holder adjacentthe protection device receiving region; means for directly mounting theprotection device to the body when the removable portion is removed; andmeans for directly mounting the body to a chassis.
 2. The finger guardof claim 1, wherein the means for directly mounting the protectiondevice to the body when the removable portion is removed includes anopening for receiving a removable fastener for mounting the protectiondevice to the body.
 3. The finger guard of claim 1, wherein the meansfor directly mounting the body to the chassis includes an opening forreceiving a removable fastener for mounting the body to the chassis. 4.The finger guard of claim 1, further comprising a raised guardpositioned about the protection device receiving region, the raisedguard including a pair of opposing finger grips, one of the finger gripson each of a top wall and a bottom wall of the raised guard.
 5. Thefinger guard of claim 4, wherein the designation holder is positionedoutside of the raised guard adjacent the top wall or the bottom wall ofthe raised guard.
 6. An electrical power distribution system comprising:a chassis including at least one electrical circuit protective devicemounting location; a face of the chassis including an opening throughwhich an electrical circuit protection device may be inserted into theat least one mounting location; a guard mounted to the face blocking atleast a portion of the opening of the face and preventing access to theat least one mounting location, the guard including: a body defining aprotection device receiving region; a removable portion blocking receiptof the protection device in the protection device receiving region; adesignation holder adjacent the protection device receiving region;means for directly mounting the protection device to the body when theremovable portion is removed; and means for directly mounting the bodyto the face of the chassis.
 7. The system of claim 6, the guard furthercomprising a switch guard adjacent the protection device receivingregion.
 8. A finger guard for an electrical circuit protection device,the finger guard comprising: a body defining a protection devicereceiving region; a removable portion blocking receipt of the protectiondevice in the protection device receiving region; a designation holderadjacent the protection device receiving region; a first opening forreceiving a removable fastener for directly mounting the protectiondevice to the body when the removable portion is removed; and a secondopening for receiving a removable fastener for directly mounting thebody to a chassis.